Preparation method of sandwich material of lightweight composite material and lightweight high sound insulation composite material

Abstract

The present invention provides a method for preparing a sandwich material of a lightweight composite material and a lightweight high-sound insulation composite material. The method achieves lightweighting of the composite material by adding transverse and longitudinal crisscross reinforcement ribs to the sandwich material of the composite material and reducing the density of the core material. The method is simple to operate and easy to implement. The long strips formed by bonding and cutting can better control the thickness of the sandwich when splicing it into a sandwich. By adding transverse and longitudinal reinforcement ribs, the excellent mechanical properties of the product can be achieved, and by reducing the density of the foaming material, the lightweighting of various components of rail transit can be achieved by more than 20%. The present invention also provides a lightweight high-sound insulation composite material. The use of the above-mentioned sandwich material ensures good mechanical properties and lightweighting. The application of damping materials can achieve excellent sound insulation performance of the product and meet the comfort requirements of various components of rail transit.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and more particularly to a method for preparing a sandwich material of a lightweight composite material and a lightweight high-sound insulation composite material. Background Art

[0002] The rapid development of rail transit has put forward higher requirements for vehicle comfort and lightweight, including requirements for vehicle interior materials. Vehicle interior product materials include pure phenolic foam materials and fiber-reinforced phenolic foam sandwich composite materials.

[0003] For example, the patent number is 202110014429.6, and the patent name is an invention patent for a molded composite sandwich panel, which includes an upper panel, a lower panel and a core material. The core material is located between the upper panel and the lower panel, and the upper and lower panel materials are both phenolic glass fiber prepreg cloth; the core material includes a phenolic foam material and a glass fiber reinforcement layer; the phenolic foam material is composed of a plurality of triangular prisms, the cross section of the triangular prism is a right triangle, and the side where one of the right-angled sides of the cross section is located is bonded to the upper panel or the lower panel; the surface of the triangular prism is covered with the glass fiber reinforcement layer. The present invention effectively solves the problems of easy delamination, poor load-bearing capacity, easy corrosion, and poor flame retardancy of ordinary composite panels, while also improving their sound insulation and impact resistance. The sandwich panel core material described in this patent has no fiber reinforcement, and its mechanical properties are poor compared to the use of fiber-reinforced phenolic foam sandwich composite materials. Therefore, it is necessary to use multiple triangular prisms for reinforcement to achieve higher mechanical properties, but this does not meet the requirements of lightweighting.

[0004] For example, the patent number is 202022162627.0, and the patent name is a utility model patent for a phenolic composite multi-layer sandwich panel for rail transit, which includes a panel located on the outermost side of the panel, a sound insulation board located in the center of the panel, and a phenolic foam core board located between the panel and the sound insulation board. The sound insulation board and the phenolic foam core board are vacuum-introduced into an integral structure with the panel, and the panel completely wraps the sound insulation board and the phenolic foam core board. The panel of the present invention utilizes a structure in which the sound insulation board and the phenolic foam core board are enclosed in the panel to achieve excellent fire retardant, low density, and sound insulation performance, meeting the high sound insulation, flame retardant and structural strength requirements of rail transit, and can be used in floors, wheel well covers, etc.; the panel is vacuum-introduced into an integral molding method to completely enclose the sound insulation board and the phenolic foam core board, thereby improving the structural strength of the panel. This patent has excellent fire retardant functions, and at the same time improves the structural strength of the panel by adopting a vacuum-introduced integral molding method. The effect of improving the structural strength of the panel in this way is not great, and the patent does not involve improvements in lightweighting.

[0005] Another example is the patent application number 201710276805.2, and the patent name is an invention patent for a phenolic foam floor and its preparation method. The phenolic foam floor prepared by this invention has excellent fire resistance and fire resistance, does not burn when exposed to open flames, and emits little smoke. It is non-toxic, smokeless, and dripless, and will not cause pollution to the environment. It is environmentally friendly and low-carbon. In addition, it has the properties of penetration resistance and good sound insulation effect, and is light in weight and saves materials. The raw materials of phenolic resin are easy to obtain and inexpensive, which greatly reduces the preparation cost. While ensuring the mechanical properties, it has good thermal insulation performance.

[0006] For example, patent number 201510588042.6, titled "A Method for Preparing and Applying a Lightweight Panel Made of Phenolic Foam Composite Material," includes steps such as preparing a modified phenolic resin impregnation solution, dipping glass wool into the modified phenolic resin impregnation solution for resin immersion, gluing, drying, and foaming to shape the panels. This patent lacks a systematic study of the lightweighting and sound insulation of the panels.

[0007] All of the above patents describe pure phenolic foam composite materials. Currently, fiber-reinforced phenolic foam sandwich composite materials are increasingly being used in the field of rail transit due to their flame retardancy, light weight, excellent sound insulation and shock absorption properties. Their mechanical properties and lightweightness are superior to pure phenolic foam composite materials. For example, patent number 201320046192.0, titled "A Utility Model Patent for a New Flame-Retardant Lightweight Panel," consists of a panel layer and a core panel. The core panel is a fiber-reinforced phenolic resin foam panel, each having at least one panel layer on the upper and lower sides, and the materials of the adjacent two panel layers are different. The present invention uses a phenolic foam panel made of glass fiber fabric reinforced phenolic foam as the core panel. By adjusting the number of panel layers on the upper and lower sides, different mechanical properties are achieved. The panel also has multiple properties, such as sound absorption, sound insulation, fire resistance, impact resistance, non-toxicity, and non-water absorption, meeting the requirements of different application fields. Since fiber-reinforced phenolic foam material already has high mechanical properties, it does not require triangular prism reinforcement as in Patent 202110014429.6. It is simple to manufacture and easy to operate, and has a large operating space.

[0008] However, the fiber-reinforced phenolic foam materials currently used in rail transit are bare boards. Due to the increasingly high requirements for comfort and lightweight, the requirements for lightweight materials used in rail transit have also been raised, and comfort includes sound insulation performance. The existing technology cannot achieve a match between lightweight and high sound insulation through the combination of bare fiber-reinforced phenolic foam materials and sound insulation materials, making it difficult to carry out large-scale product replacement for components that require high sound insulation and lightweight. Therefore, with the continuous increase in lightweight, comfort, product performance and energy-saving and environmental protection requirements for rail transit interior products, it is necessary to further optimize fiber-reinforced phenolic foam sandwich composite materials. The preparation of lightweight and high sound insulation fiber-reinforced phenolic foam sandwich composite materials is the development direction of the application of phenolic foam composite materials in rail transit. While being lightweight, it is also necessary to ensure higher mechanical properties and better sound insulation performance. How to resolve the contradiction between lightweight and mechanical properties, and the contradiction between lightweight and sound insulation performance are difficult technical problems to solve. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a method for preparing a sandwich material of a lightweight composite material in response to the ever-increasing requirements for lightweight and comfort of rail transit interior products. The composite material manufactured by this method not only has high mechanical properties, but also can significantly reduce the weight of the composite material to achieve lightweighting, thereby resolving the contradiction between lightweighting and mechanical properties.

[0010] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0011] A method for preparing a sandwich material of a lightweight composite material, wherein the lightweight composite material is achieved by adding transverse and longitudinal reinforcing ribs to the sandwich material of the composite material and reducing the density of the core material, comprising the following steps:

[0012] S1: Bonding the core material onto the panel 1 to produce prefabricated panel 1;

[0013] S2: perpendicular to the direction of panel 1, cut the prefabricated panel 1 into strips 1 of equal size; one side of the strip 1 is panel 1, and the other side is core material;

[0014] S3: Bonding the cut strips 1 to panel 2 row by row, with panel 1 perpendicular to panel 2; bonding the core material in strip 1 to panel 1 of another strip 1; and making prefabricated panel 2;

[0015] S4: cutting the prefabricated panel 2 in a direction perpendicular to the panel 1 and the panel 2; cutting the prefabricated panel 2 into strips 2 of equal size; the strips 2 are hexahedral structures;

[0016] S5: bonding the two strips row by row and column by column to form a sandwich material with reinforcing ribs staggered horizontally and vertically;

[0017] Among them, the material of panel 1 and panel 2 is the material of the reinforcing ribs.

[0018] The method described herein improves composite sandwich materials by adding crisscrossing ribs to the core. The crisscrossing ribs are simple to form, and their size is easily controlled. The ribs are distributed both on the surface and within the core, resulting in uniform force distribution within the composite material and improving the stiffness of the core material in both directions. The crisscrossing ribs improve the mechanical properties of the core material, thereby reducing the density of the core material and achieving lightweighting.

[0019] The strips formed in step S2 consist of one layer of reinforcement and one layer of core material. These strips are then vertically bonded to panel 2, row by row, and then cut a second time. After step S3, prefabricated panels 2 can be stacked layer by layer to create a crisscross pattern of reinforcement, but this method makes the resulting sandwich difficult to control in size. The present invention, after forming prefabricated panel 2, cuts the prefabricated panel 2 into smaller strips, making it easier to control its thickness.

[0020] Furthermore, the core material is a fiber-reinforced phenolic foam material with a density of 100-300 kg / m 3 .

[0021] The core material is preferably a fiber-reinforced phenolic foam material. The fiber-reinforced phenolic foam material itself has high mechanical properties. Combined with the horizontal and vertical staggered reinforcement ribs, it can be lightweight to a greater extent while maintaining or improving the mechanical properties.

[0022] Furthermore, the spacing between the reinforcing ribs is 30-60 mm, and the thickness is 0.2-1 mm; therefore, in step S1, the thickness of the core material is 30-60 mm. The space between each pair of reinforcing ribs is the core material, and the spacing between the reinforcing ribs is the thickness of the core material in step S1.

[0023] Furthermore, in step S2, the cutting thickness of the prefabricated panel 1 is 30-60 mm; and in step S4, the cutting thickness of the prefabricated panel 2 is inversely proportional to the stiffness of the composite material.

[0024] Furthermore, the material of the reinforcing rib is one or more of epoxy-based composite material, phenolic-based composite material, and phenolic-epoxy-based composite material.

[0025] The above numerical settings can achieve a 20% weight reduction under the same mechanical performance requirements, and a 50% improvement in mechanical performance under the same weight reduction conditions, thus resolving the contradiction between lightweighting and mechanical performance.

[0026] The lightweight composite material described in the present invention also solves the problem of precision. Specifically, since the core material is made of fiber-reinforced phenolic foam material, the fiber-reinforced phenolic foam material used in existing rail transit is a bare plate, which is usually pressed from multiple pieces. Due to the difference in force in each direction and the relatively soft material, the precision of the bare plate of fiber-reinforced phenolic foam material pressed by the press can only be controlled to be above 0.5mm. The present invention adds reinforcing ribs to first make prefabricated plate one, cut it into a certain width, and then bond it into prefabricated plate two, and then cut it into the width required for the product. The cutting width precision can be controlled to 0.1mm. Because of the support of the reinforcing ribs, the sandwich core has higher strength, so the subsequent pressing into the product can be well controlled in terms of precision.

[0027] The present invention also provides a lightweight, high-sound insulation composite material, comprising an upper panel, a lower panel, and a sandwich material located between the upper panel and the lower panel, wherein the sandwich material is prepared using the method for preparing a sandwich material of the lightweight composite material described above.

[0028] Furthermore, the materials of the upper panel and the lower panel are one or more of epoxy-based composite materials, phenolic-based composite materials, and phenolic-epoxy-based composite materials.

[0029] Furthermore, a damping layer is bonded onto the upper panel or the lower panel.

[0030] Furthermore, the damping layer is made of a soft material, which is a composite material of butyl rubber and aluminum foil.

[0031] The materials of the upper and lower panels of the present invention have good sound insulation effects on medium and high frequencies, and the damping layer is made of soft materials with good sound insulation effects on low frequencies. The combination of the upper and lower panels and the damping layer can achieve good sound insulation effects.

[0032] Furthermore, the density of the damping layer is 1500~1600kg / m 3 , the thickness of aluminum foil is 0.1~0.3mm.

[0033] The above setting can increase the damping layer by about 1dB for every 1kg increase, which can solve the contradiction between lightweight and sound insulation performance.

[0034] The composite material is a lightweight and highly sound-insulating fiber-reinforced phenolic foam composite material, which is lightweight while having high mechanical properties and good sound insulation performance, and has great technical and market prospects.

[0035] The present invention has the following beneficial effects:

[0036] The method for preparing a lightweight composite sandwich material, described herein, incorporates crisscrossing reinforcement ribs within the core material. This method is simple and easy to implement. The resulting strips, formed by bonding and cutting, can be assembled to form a sandwich with better control over its thickness. The addition of transverse and longitudinal reinforcements achieves excellent mechanical properties and reduces the density of the foamed material, potentially reducing the weight of rail transit components by over 20%.

[0037] The present invention also provides a lightweight and highly sound-insulating composite material. The above-mentioned sandwich material is used to ensure good mechanical properties and lightweight. The application of damping materials can achieve excellent sound insulation performance of the product and meet the comfort requirements of various components of rail transit. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0039] Figure 1 This is a schematic diagram of the prefabricated panel in step S1.

[0040] Figure 2 This is a schematic diagram of prefabricated panels and cutting directions.

[0041] Figure 3 It is a schematic diagram of a long strip formed by cutting a prefabricated board.

[0042] Figure 4 This is a schematic diagram of the row-by-row bonding of strip 1 and panel 2.

[0043] Figure 5 This is a schematic diagram of prefabricated panel 2.

[0044] Figure 6 It is a schematic diagram of the second long strip.

[0045] Figure 7 It is a long schematic diagram ( Figure 6 Strip 2 rotates 180 degrees).

[0046] Figure 8 It is a schematic diagram of two long strips spliced together to form horizontal and vertical staggered reinforcement ribs.

[0047] Figure 9 It is a schematic diagram of the composite material structure.

[0048] Panel one-1, panel two-2, core material-3, upper panel 4, lower panel 5, reinforcement rib 6, damping layer 7. DETAILED DESCRIPTION

[0049] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims. Example 1

[0050] A method for preparing a sandwich material of a lightweight composite material, wherein the lightweight composite material is achieved by adding transverse and longitudinal reinforcing ribs to the sandwich material of the composite material and reducing the density of the core material, comprising the following steps:

[0051] S1: Bond the core material 3 on the panel 1 to make a prefabricated panel 1. Figure 1 Shown is precast panel 1;

[0052] S2: If Figure 2 As shown, perpendicular to the direction of panel 1, the prefabricated panel 1 is cut into strips 1 with a width of a; one side of the strip is panel 1, and the other side is core material (such as Figure 3 Shown is the long bar 1);

[0053] S3: If Figure 4 As shown, the cut strips 1 are glued to the panel 2 2 in rows, with the panel 1 1 perpendicular to the panel 2 2; the core material 3 in the strip 1 is glued to the panel 1 1 of another strip 1; and a prefabricated panel 2 (such as Figure 5 Precast panel 2 is shown);

[0054] S4: As Figure 5 As shown, the prefabricated panel 2 is cut in a direction perpendicular to the panel 1 and the panel 2; the prefabricated panel 2 is cut into strips 2 with a width of b; Figure 6 As shown, the second strip is a hexahedral structure;

[0055] S5: Glue the strips row by row and column by column. Figure 8 As shown, Figure 6 The strips are bonded row by row to form a sandwich material with crisscrossed ribs. Figure 8 The crisscross structure formed by cutting and splicing panel one and panel two is the reinforcement rib.

[0056] like Figure 6 and Figure 7 As shown, Figure 7 for Figure 6 After rotating 180 degrees, except for the end of the hexahedron, only the side away from panel 2 includes two opposite edges, without panel 1 or panel 2, that is, without reinforcement ribs; when splicing, the side without reinforcement ribs is spliced with the side with reinforcement ribs.

[0057] The core material is a fiber-reinforced phenolic foam material with a density of 100-300 kg / m 3 .

[0058] The spacing between the reinforcing ribs is 30-60 mm, and the thickness is 0.2-1 mm; therefore, in step S1, the thickness of the core material is 30-60 mm. The space between each pair of reinforcing ribs is the core material, and the spacing between the reinforcing ribs is the thickness of the core material in step S1.

[0059] In step S2, the cutting thickness of the prefabricated panel 1 is 30-60 mm; in step S4, the cutting thickness of the prefabricated panel 2 is inversely proportional to the stiffness of the composite material.

[0060] The material of the reinforcing rib is one or more of an epoxy-based composite material, a phenolic-based composite material, and a phenolic-epoxy-based composite material. Example 2

[0061] A lightweight, highly sound-insulating composite material, used for the floor of a rail transit vehicle, comprises an upper panel 4, a lower panel 5, and a sandwich material located between the upper panel 4 and the lower panel 5. The composite material is prepared using the method for preparing the sandwich material of the lightweight composite material described in Example 1.

[0062] The material of the upper panel 4 and the lower panel 5 is 1mm epoxy composite material. Figure 9 As shown, the sandwich material includes a core material 3 and reinforcing ribs 6, wherein the reinforcing ribs 6 are reinforcing ribs staggered horizontally and vertically.

[0063] The core material 3 is a fiber-reinforced phenolic foam material with a density of 100 kg / m 3 .

[0064] The material of the reinforcing ribs 6 is an epoxy-based composite material, the spacing between the reinforcing ribs 6 is 30 mm, and the thickness is 1 mm.

[0065] A 1 mm damping layer 7 is also bonded to the lower panel 5. The material of the damping layer 7 is a composite material of butyl rubber and aluminum foil. The density of the damping layer 7 is 1500 kg / m 3 , the thickness of the aluminum foil is 0.1mm.

[0066] After testing, its surface density is 8.5kg / m 2 , sound insulation reaches 29dB, bending strength is 365 / MPa. The bending strength of the floor is required to be ≥200MPa. Example 3

[0067] The difference between Example 3 and Example 2 is that the density of the fiber-reinforced phenolic foam material is 250 kg / m 3 , after testing, its surface density is 10.5kg / m 2 , sound insulation reaches 29dB, and bending strength is 382 / MPa. Example 4

[0068] The difference between Example 4 and Example 3 is that the density of the fiber-reinforced phenolic foam material is 300 kg / m 3 , after testing, its surface density is 11.8kg / m 2 , the sound insulation reaches 29.1dB, and the bending strength is 423 / MPa. Example 5

[0069] The difference between Example 5 and Example 2 is that the thickness of the reinforcing rib is 0.5 mm, and its surface density is 8.0 kg / m 2 , the sound insulation reaches 28.4dB, and the bending strength is 325 / MPa. Example 6

[0070] The difference between Example 6 and Example 2 is that the spacing of the reinforcing ribs is 60 mm, and the surface density is 8.0 kg / m 2 , the sound insulation reaches 28.6dB, and the bending strength is 298 / MPa. Example 7

[0071] The difference between Example 7 and Example 2 is that the thickness of the aluminum foil is 0.3 mm, and its surface density is 9.1 kg / m 2 , the sound insulation reaches 29.5dB, and the bending strength is 368 / MPa. Example 8

[0072] The difference between Example 8 and Example 2 is that the density of the damping layer is 1600 kg / m 3 , after testing, its surface density is 8.6kg / m 2 , the sound insulation reaches 29.2dB, and the bending strength is 296 / MPa. Comparative Example 1

[0073] The difference between Comparative Example 1 and Example 2 is that no reinforcing ribs are provided. After testing, the surface density is 7.9 kg / m 2 , the sound insulation reaches 28.4dB, and the bending strength is 243 / MPa. Comparative Example 2

[0074] The difference between Comparative Example 2 and Example 2 is that no damping layer is provided. After testing, its surface density is 7.0 kg / m 2 , the sound insulation reaches 27.5dB, and the bending strength is 274 / MPa. Comparative Example 3

[0075] Comparative Example 3 differs from Example 2 in that no reinforcing ribs are provided. After testing, the surface density thereof is 9.8 kg / m 2 , the sound insulation reaches 27.8dB, and the bending strength is 306 / MPa.

[0076] Table 1: Performance test results of Examples 1-8 and Comparative Examples 1-2

[0077]

[0078] The core material density, rib spacing, rib thickness, damping layer density, and aluminum foil thickness of Examples 2 to 8 are all within the scope of this application, and the bending strength can meet the bending strength requirements of the floor.

[0079] Comparing Examples 2, 3, and 4, we can see that the greater the core material density, the greater the surface density (heavier the mass), and the greater the bending strength. This means that increasing the core material density can improve the floor's bending strength, but at the expense of increased weight.

[0080] Comparing Example 2 and Example 5, we can see that the smaller the rib thickness, the lower the bending strength. Comparing Example 2 and Example 6, we can see that the larger the rib spacing, the lower the bending strength. Rib thickness and rib spacing affect the bending strength of the floor.

[0081] Comparing Example 2 and Example 7, it can be seen that the thicker the aluminum foil, the greater the sound insulation. Comparing Example 2 and Example 8, it can be seen that the greater the density of the damping layer, the greater the sound insulation. The thicker the aluminum foil and the greater the density of the damping layer, the greater the sound insulation.

[0082] By comparing Example 2 with Comparative Example 1, it can be seen that when no reinforcing ribs are used, the bending strength is significantly reduced.

[0083] By comparing Example 2 and Comparative Example 2, it can be seen that when the damping layer is not used, the sound insulation is significantly reduced.

[0084] Comparing Example 2 and Comparative Example 3, it can be seen that the core material density of Example 2 is much lower than that of Comparative Example 3. Example 2 uses reinforcing ribs, while Comparative Example 3 does not. This comparison also shows that even with the higher core material density of Comparative Example 3, the bending strength is significantly lower than when reinforcing ribs are used. Therefore, the composite material with crisscrossing reinforcing ribs of the present invention achieves maximum lightweighting while improving mechanical properties.

[0085] In summary, the analysis of Examples 2-8 and Comparative Examples 1-3 shows that higher core material density increases bending strength, but is detrimental to lightweighting. Using crisscross reinforcing ribs not only achieves greater bending strength but also allows for the use of a lower-density core material, ensuring both bending strength and lightweighting. Using a soft material for the damping layer provides excellent sound insulation.

[0086] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of the present invention.

Claims

1. A method for preparing a sandwich material of a lightweight composite material, characterized in that: The lightweighting of the composite material is achieved by adding horizontal and vertical crisscross reinforcement ribs to the sandwich material of the composite material and reducing the density of the core material, including the following steps: S1: Bonding the core material onto the panel 1 to produce prefabricated panel 1; S2: perpendicular to the direction of panel 1, cut the prefabricated panel 1 into strips 1 of equal size; one side of the strip 1 is panel 1, and the other side is core material; S3: Bonding the cut strips 1 to panel 2 row by row, with panel 1 perpendicular to panel 2; bonding the core material in strip 1 to panel 1 of another strip 1; and making prefabricated panel 2; S4: cutting the prefabricated panel 2 in a direction perpendicular to the panel 1 and the panel 2; cutting the prefabricated panel 2 into strips 2 of equal size; the strips 2 are hexahedral structures; S5: bonding the two strips row by row and column by column to form a sandwich material with reinforcing ribs staggered horizontally and vertically; Among them, the material of panel 1 and panel 2 is the material of the reinforcing ribs.

2. The method for preparing a sandwich material of a lightweight composite material according to claim 1, characterized in that: The core material is a fiber-reinforced phenolic foam material with a density of 100-300 kg / m 3 .

3. The method for preparing a sandwich material of a lightweight composite material according to claim 1, characterized in that: The spacing of the reinforcement ribs is 30~60mm and the thickness is 0.2~1mm.

4. The method for preparing a sandwich material of a lightweight composite material according to claim 1, characterized in that: In step S2, the cutting thickness of the prefabricated panel 1 is 30-60 mm; in step S4, the cutting thickness of the prefabricated panel 2 is inversely proportional to the stiffness of the composite material.

5. The method for preparing a sandwich material of a lightweight composite material according to claim 1, characterized in that: The material of the reinforcing rib is one or more of an epoxy-based composite material, a phenolic-based composite material, and a phenolic-epoxy-based composite material.

6. A lightweight, highly sound-insulating composite material comprising an upper panel, a lower panel, and a sandwich material located between the upper and lower panels, characterized in that: The sandwich material is a sandwich material prepared using the method for preparing a sandwich material of a lightweight composite material according to any one of claims 1 to 5.

7. The lightweight and highly sound-insulating composite material according to claim 6, characterized in that: The materials of the upper panel and the lower panel are one or more of epoxy-based composite materials, phenolic-based composite materials, and phenolic-epoxy-based composite materials.

8. The lightweight and highly sound-insulating composite material according to claim 7, characterized in that: A damping layer is also bonded to the upper panel or the lower panel.

9. The lightweight and highly sound-insulating composite material according to claim 8, characterized in that: The material of the damping layer is soft material.

10. The lightweight and highly sound-insulating composite material according to claim 9, characterized in that: The density of the damping layer is 1500~1600kg / m 3 , the thickness of aluminum foil is 0.1~0.3mm.

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